in the market to purchase some sd cards for my D7100 before a trip to England .

I don't shoot in bursts normally. My subjects are typically landscapes and travel city shots. Occasionally I will bracket 5 shots for HDR work. i also may occasionally film short sequences, but not very long takes.

Based upon type of shooting , what speed cards do I need?

For videoing and just general shooting the 30mb/s cards will be about okay. If you head anywhere where you will want to do bursts 45mb/s or 95mb/s will be better for write speed. Be sure to take a few smaller cards rather than one large one just incase one becomes misplaced. It happens!